I also use the medical analogy when I'm discussing mental health... only because I think some people associate mental health with "MOOD". Being depressed isn't the same as feeling sad. There may be sadness involved, but being depressed isn't simply being in a negative mood. I believe, from what I've read over the years, that there is a physiological element to mental illness. So... I explain that just as one might treat diabetes (or another medical conditon)with both medicine AND lifestyle choices, they might also treat mental illness with both medicine and life style choices.